*{
    margin: 0;
    padding: 0;
    list-style: none;
}
.margin{
    margin: 0 auto;
}
.t-center{
   text-align:center;
}
.border1{
    border: 1px solid red;
}
.f-l{
    float: left;
}
.f-r{
    float: right;
}
.overhidden{
    overflow: hidden;
}
.flex{
    display: flex;
}
.justify{
    justify-content: space-between;
}
.cursor{
    cursor: pointer;
}
.clear{
    clear:both;
}